U.S. Pat. No. 4,332,435 issued Jun. 1, 1982, in the name of Jan Post to N. K. F. Groep B. V., Netherlands for "Glass Fiber Cable" discloses an arrangement wherein optical fibers of two separate optical cables are coupled together by splices contained within the housing of a junction box. These cables are introduced into the box by their passages through respective openings in end plates of the box and then into the space enclosed by the housing.
For cable strain relief purposes, a feed-through bush is inserted from the inside of the box into the opening in each plate to pass through and beyond that opening. The bush contains the cable and has shoulders bearing against the inside wall surface of that plate. The bush contains a gasket adjacent to such plate and encircling the cable in such opening. A union disposed in such bush outward of the gasket (and also encircling the cable) is threadedly engaged with the bush to be adapted by turning of the union to compress the gasket to thereby clamp the cable in and to the bush. By virtue of that clamping and of the bearing of the bush shoulders against the mentioned end plate, the cable portion inside the box will be relieved of strain from pulling force exerted on the cable outside the box. The passage of the cable through the end plate opening is sealed by a water-tight envelope shrunk onto the bush on the outside of the box.
While the described arrangement provides a seal for the passage of the cable through the wall opening, it has the disadvantages that it is expensive in construction, requires that the cable be passed through the bush by end entry rather than side entry thereinto, will not accommodate to the extent desirable a range of variation in cable diameter, cannot be used as a seal in the absence of the cable and cannot be used for passage of more than one cable through the same opening.